Biotechnology-based pharmaceuticals, which utilize biomacromolecules such as proteins and nucleic acids, are more susceptible to enzymatic degradation or immune elimination, compared with conventional pharmaceuticals based on low-molecular compounds. Patent Documents 1 to 4 disclose a DDS which contains a biomacromolecule within a liposome made of a lipid bilayer membrane, which intends to improve the in vivo stability of biotechnology-based pharmaceuticals.